Differences in the processing of visual stimuli by the ambient and focal systems will be studied with respect to luminance, refractive error, dynamic spatial orientation, and posture in both normals and neurological and ophthalmological patients. Of particular interest is the residual visual function not indicated by conventional perimetric examination, and its role in spatial orientation. The effect of stess and cervical nerve damage on accommodation will be studied with particular reference to the innervation supplied by the autonomic nervous system. The role of the vestibular and oculomotor systems with respect to the autokinetic phenomenon will be analyzed. BIBLIOGRAPHIC REFERENCES: H. Leibowitz, Visual Perception and Hyponosis, in Psychological Research; The Inside Story, edited by H. P. Zeigler and M. Siegel, Harper & Row, 1976. R.J. Miller and H. Leibowitz. A signal detection analysis of hypnotically-induced narrowing of the peripheral visual field, Journal of Abnormal Psychology, 1976.